Transformer and method of manufacturing the same

ABSTRACT

Disclosed herein are a transformer and a method of manufacturing the same. The transformer includes: a primary side winding having a loop shape; a secondary side winding formed on the same plane as that of the primary side winding in a remaining section except for at least a section at which it intersects with the primary side winding and having the same loop shape as that of the primary side winding so as to be electromagnetically coupled to the primary side winding; and an intersecting section formed so that the primary side and secondary side windings having the sum of the turn numbers of 3 or more intersect with each other in a two-layer structure, wherein the intersecting section includes at least one point of intermediate node having one side connected in a first layer and the other side connected in a second layer.

CROSS REFERENCE(S) TO RELATED APPLICATIONS

This application is a Reissue Application from U.S. Pat. No. 8,493,169issued on Jul. 23, 2013 and filed Nov. 20, 2012, which claims thebenefit under 35 U.S.C. Section 119 of Korean Patent Application SerialNo. 10-2011-0122338, entitled “Transformer and Method of Manufacturingthe Same” filed on Nov. 22, 2011, which is are hereby incorporated byreference in its entirety their entireties into this application.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a transformer and a method ofmanufacturing the same, and more particularly, to a transformer in whichthree or more lines of a primary side and a secondary side intersectwith each other in a two-layer structure, and a method of manufacturingthe same.

2. Description of the Related Art

The present invention relates to a transformer used for matching andimpedance conversion of a high frequency power amplifier used in acommunication system. In a power amplifying module or a transceivingmodule, a power combiner necessarily used together with an amplifierdevice manufactured by a complementary metal oxide semiconductor (CMOS)process is generally an integrated passive device (IPD) typetransformer. For example, in the case of a CMOS one-chip poweramplifier, a method of combining parallel-amplified signals with eachother is required. In this case, a transformer for combining power isrequired. The transformer for combining power serves to minimize losswhile combining amplified powers with each other.

Describing a structure of a transformer according to the related art, itmay be understood that an intersecting section shown in FIG. 2A isreplaced with an intersecting section of FIG. 1. Here, an input sideprimary winding and an output side secondary winding are designed to beelectromagnetically coupled to each other in a form in which they areopened. In the case in which the twisted turn number of output side orinput side conductive lines is 2 or more, three or more connection linelayers are generally used as shown in FIG. 2A.

In the case of a general semiconductor process, a thick metal layerthrough which a passive device may be designed is mainly configured oftwo layers. Therefore, in the case of using three or more layers as inthe related art, a thickness of the metal layer becomes thin, such thatefficiency of the transformer may be significantly deteriorated at thetime of design of the transformer.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a transformer capableof having improved efficiency by allowing a line intersecting structureincluding three or more lines of a primary side and a secondary side tobecome a two-layer structure.

According to an exemplary embodiment of the present invention, there isprovided a transformer including: a primary side winding having a loopshape; a secondary side winding formed on the same plane as that of theprimary side winding in a remaining section except for at least asection at which it intersects with the primary side winding and havingthe same loop shape as that of the primary side winding so as to beelectromagnetically coupled to the primary side winding; and anintersecting section formed so that the primary side and secondary sidewindings having the sum of the turn numbers of 3 or more intersect witheach other in a two-layer structure, wherein the intersecting sectionincludes at least one point of intermediate node having one sideconnected in a first layer and the other side connected in a secondlayer.

At least one pair of outermost lines facing each other in a diagonaldirection in the intersecting section among the three or more windingturns may be connected to each other in the first or second layer in thediagonal direction.

At least one sub-outermost line among the three or more winding turnsmay be connected to the intermediate node in the first or second layerin the intersecting section.

The sum of the turn numbers of the primary and secondary side windingsmay be an odd number, at least one pair of outermost lines facing eachother in a diagonal direction in the intersecting section among the oddwinding turns may be connected to each other in the first or secondlayer in the diagonal direction, and a pair of sub-outermost linesfacing each other normally directly or obliquely in the intersectingsection among the odd winding turns may be connected to each otherthrough the intermediate node so as not to contact a connection line ofthe pair of outermost lines in the intersecting section, wherein one ofthe pair of sub-outermost lines is connected to the intermediate node inthe first layer and the other thereof is connected to the intermediatenode in the second layer.

The sum of the turn numbers of the primary and secondary side windingsmay be an odd number of 5 or more, and one of the pair of sub-outermostlines facing each other obliquely in the intersecting section among theodd winding turns is connected to the intermediate node in the firstlayer and the other thereof may be connected to the intermediate node inthe second layer, wherein remaining lines among the odd winding turnsare obliquely connected to each other in the other layer unlike that ofthe connection line of the pair of outermost lines so as to intersectwith the connection line on a floor plane in the intersecting section.

The sum of the turn numbers of the primary and secondary side windingsmay be an even number, the intermediate nodes may be two points and faceeach other based on the center of the intersecting section, at least onepair of outermost lines facing each other in a diagonal direction in theintersecting section among the even winding turns may be connected toeach other in the first or second layer in the diagonal direction, andat least one pair of sub-outermost lines facing each other normallydirectly or obliquely in the intersecting section among the even windingturns may be connected to each other through the intermediate node so asnot to contact a connection line of the pair of outermost lines in theintersecting section, wherein one of the pair of sub-outermost lines isconnected to the intermediate node in the first layer and the otherthereof is connected to the intermediate node in the second layer.

The sum of the turn numbers of the primary and secondary side windingsmay be an even number of 6 or more, one of the pair of sub-outermostlines facing each other obliquely in the intersecting section among theeven winding turns may be connected to one intermediate node in thefirst layer and the other thereof may be connected to one intermediatenode in the second layer, and one of another pair of lines facing eachother normally directly or obliquely in the intersecting section amongthe even winding turns may be connected to the other intermediate nodein the first layer and the other thereof may be connected to the otherintermediate node in the second layer, wherein remaining lines among theeven winding turns are obliquely connected to each other in the otherlayer unlike that of the connection line of the pair of outermost linesso as to intersect with the connection line on a floor plane in theintersecting section.

Any one of the primary and secondary side windings may be a balancedsignal line and the other thereof may be an unbalanced signal line.

According to another exemplary embodiment of the present invention,there is provided a method of manufacturing a transformer including aprimary side winding having a loop shape and a secondary side windingformed on the same plane as that of the primary side winding and havingthe same loop shape as that of the primary side winding so as to beelectromagnetically coupled to the primary side winding, the methodincluding: forming an intersecting section so that the primary side andsecondary side windings having the sum of the turn numbers of 3 or moreintersect with each other in a two-layer structure, wherein theintersecting section includes at least one point of intermediate nodehaving one side connected in a first layer and the other side connectedin a second layer.

At least one pair of outermost lines facing each other in a diagonaldirection in the intersecting section among the three or more windingturns may be connected to each other in the first or second layer in thediagonal direction.

At least one sub-outermost line among the three or more winding turnsmay be connected to the intermediate node in the first or second layerin the intersecting section.

The sum of the turn numbers of the primary and secondary side windingsmay be an odd number, at least one pair of outermost lines facing eachother in a diagonal direction in the intersecting section among the oddwinding turns may be connected to each other in the first or secondlayer in the diagonal direction, and a pair of sub-outermost linesfacing each other normally directly or obliquely in the intersectingsection among the odd winding turns may be connected to each otherthrough the intermediate node so as not to contact a connection line ofthe pair of outermost lines in the intersecting section, wherein one ofthe pair of sub-outermost lines is connected to the intermediate node inthe first layer and the other thereof is connected to the intermediatenode in the second layer.

The sum of the turn numbers of the primary and secondary side windingsmay be an even number, the intermediate nodes may be two points and faceeach other based on the center of the intersecting section, at least onepair of outermost lines facing each other in a diagonal direction in theintersecting section among the even winding turns may be connected toeach other in the first or second layer in the diagonal direction, andat least one pair of sub-outermost lines facing each other normallydirectly or obliquely in the intersecting section among the even windingturns may be connected to each other through the intermediate node so asnot to contact a connection line of the pair of outermost lines in theintersecting section, wherein one of the pair of sub-outermost lines isconnected to the intermediate node in the first layer and the otherthereof is connected to the intermediate node in the second layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view schematically showing a transformer according to anexemplary embodiment of the present invention;

FIGS. 2A and 2B are, respectively, a view schematically showing anintersecting section of a transformer according to the related art and aview schematically showing an intersecting section of the transformer ofFIG. 1;

FIG. 3 is a view schematically showing an intersecting section of atransformer according to another exemplary embodiment of the presentinvention;

FIG. 4 is a view schematically showing an intersecting section of atransformer according to still another exemplary embodiment of thepresent invention;

FIG. 5 is a view schematically showing an intersecting section of atransformer according to still another exemplary embodiment of thepresent invention; and

FIG. 6 is a view schematically showing an intersecting section of atransformer according to still another exemplary embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Exemplary embodiments of the present invention for accomplishing theabove-mentioned objects will be described with reference to theaccompanying drawings. In describing exemplary embodiments of thepresent invention, the same reference numerals will be used to describethe same components and an additional description that is overlapped orallow the meaning of the present invention to be restrictivelyinterpreted will be omitted.

In the specification, it will be understood that unless a term such as‘directly’ is not used in a connection, coupling, or dispositionrelationship between one component and another component, one componentmay be ‘directly connected to’, ‘directly coupled to’ or ‘directlydisposed to’ another element or be connected to, coupled to, or disposedto another element, having the other element intervening therebetween.In addition, this may also be applied to terms including the meaning ofcontact such as ‘on’, ‘above’, ‘below’, ‘under’, or the like. In thecase in which a standard element is upset or is changed in a direction,terms related to a direction may be interpreted to including a relativedirection concept.

Although a singular form is used in the present description, it mayinclude a plural form as long as it is opposite to the concept of thepresent invention and is not contradictory in view of interpretation oris used as clearly different meaning. It should be understood that“include”, “have”, “comprise”, “be configured to include”, and the like,used in the present description do not exclude presence or addition ofone or more other characteristic, component, or a combination thereof.

The accompanying drawings referred in the present description may beideal or abstract examples for describing exemplary embodiments of thepresent invention. In the accompanying drawings, a shape, a size, athickness, and the like, may be exaggerated in order to effectivelydescribe technical characteristics.

First, a transformer according to a first exemplary embodiment of thepresent invention will be described in detail with reference to theaccompanying drawings.

FIG. 1 is a view schematically showing a transformer according to anexemplary embodiment of the present invention; FIGS. 2A and 2B are,respectively, a view schematically showing an intersecting section of atransformer according to the related art and a view schematicallyshowing an intersecting section of the transformer of FIG. 1; FIG. 3 isa view schematically showing an intersecting section of a transformeraccording to another exemplary embodiment of the present invention; FIG.4 is a view schematically showing an intersecting section of atransformer according to still another exemplary embodiment of thepresent invention; FIG. 5 is a view schematically showing anintersecting section of a transformer according to still anotherexemplary embodiment of the present invention; and FIG. 6 is a viewschematically showing an intersecting section of a transformer accordingto still another exemplary embodiment of the present invention.

The transformer according to the first exemplary embodiment of thepresent invention will be described with reference to FIGS. 1, 2B, and 3to 6.

The transformer according to the present embodiment is configured toinclude a primary side winding and a secondary side winding, wherein theprimary side winding has a loop shape, and the secondary side windingformed on the same plane as that of the primary side winding in aremaining section except for at least a section at which it intersectswith the primary side winding and having the same loop shape as that ofthe primary side winding so as to be electromagnetically coupled to theprimary side winding. The present invention relates to a transformer inthe case in which the sum of the turn numbers of primary side andsecondary side windings on the same plane is 3 or more.

Here, the transformer according to the present embodiment includes anintersecting section 10 at which the primary side winding and thesecondary side winding intersect with each other. Referring to FIG. 1,the primary side and secondary side windings of which the sum of theturn number is 3 or more intersect with each other in a two-layerstructure in the intersecting section 10. In FIG. 1, a reference numeral10 indicates the intersecting section. Referring to FIGS. 2B and 3 to 6,it may be appreciated that three or more primary and secondary sidewinding lines intersect with each other in a two-layer structure.

Further, referring to FIGS. 2B and 3 to 6, in the present embodiment,the intersecting section 10 includes at least one point of intermediatenode 1 having one side connected in a first layer and the other sideconnected in a second layer.

In the present embodiment, the intersecting section 10 includes at leastone point of intermediate node 1, such that the intersecting section 10may have a two-layer structure unlike the case according to the relatedart even though the primary side and the secondary side have three ormore winding turns. Two points of intermediate nodes 1 and 1′ are shownin FIGS. 2B and 4 to 6, and one point of intermediate node 1 is shown inFIG. 3. Although not shown, the intersecting section 10 may also havethree points of intermediate nodes. For example, as a modified exampleof FIG. 5, lines b and b′ may also be connected to each other through afirst point 1 of intermediate node, lines d and d′ may also be connectedto each other through a second point 1′ of intermediate node, and thelines d and d′ may also be again connected to each other through a thirdpoint (not shown) of intermediate node formed at a region at which theydo not contact connection lines of the first layer in the intersectingsection 10. In this case, each of the lines b and b′ and the line d andd′ is not connected to each other, but may be connected to anotherterminal. As an example, in the case in which each of the primary andsecondary sides has only a pair of terminals, the number of points ofthe intermediate nodes may be one or two, and in the case in which anyone of the primary and secondary sides has two pairs of terminals, thenumber of points of the intermediate nodes may be added.

For example, the intermediate nodes 1 and 1′ may be positioned at anedge portion of the intersecting section 10 rather than a centralportion thereof. In this case, the intermediate nodes 1 and 1′ may bepositioned on extension lines of outermost lines of primary andsecondary sides.

In addition, referring to FIG. 2B, a case in which each of signals istransmitted to first and second layers in lines b and b′. In this case,an insulation layer may be provided between the first and second layersin each line of the primary and secondary sides. Also in FIGS. 3 to 6,each of signals may be transmitted to first and second layers as in thelines b and b′ of FIG. 2B. In this case, an insulation layer may beprovided between the first and second layers. In addition, referring toFIG. 2B, in the case in which the respective lines connected to eachother by a connection line in the first or second layer in theintersecting section 10 are multilayer transmission lines, they areconducted through a conductor before being connected to each other bythe connection line, such that the signal may be transmitted through theconnection line in each of the multilayer lines. For example, in FIG.2B, a line a and a line c′ are connected to each other only in thesecond layer. However, in the case in which the line a and the line c′are multilayer transmission lines, a signal in a transmission line of alower first layer may be transmitted from the line a side to aconnection line of a second layer via a conductor (not shown) and bethen transmitted from the line c′ side to an original transmission lineof the first layer through a conductor (not shown) before the line a andthe line c′ are connected to each other by the connection line. This isalso applied to the cases of FIGS. 3 to 6.

According to the present embodiment, a transformer generally connectedto an output terminal of a power amplifier is improved to reduce powerloss, thereby making it possible to improve an output of the poweramplifier.

As an example, any one of winding lines of the primary side and thesecondary side windings may be a balanced signal line and the otherthereof may be an unbalanced signal line.

In addition, referring to FIGS. 2B and 3 to 6, as an example, at leastone pair of outermost lines facing each other in a diagonal direction inthe intersecting section 10 among three or more winding turns may beconnected to each other in the first or second layer in the diagonaldirection. Here, the outermost line means an outermost portion that isin a range of the intersecting section 10 rather than an outermostportion in the entire transformer structure as shown in FIG. 1. Forexample, in the entire transformer structure of FIG. 1, an outermostline and an innermost line correspond to the outermost line. Therefore,each of two pairs of outermost lines faces each other in theintersecting section 10. According to the present embodiment, at leastone pair of outermost lines facing each other in the diagonal directionare connected to each other in the diagonal direction. In FIGS. 2B, 3,and 4, a case in which each of two pairs of outermost lines facing eachother in the diagonal direction are connected to each other in the firstand second layers in the diagonal direction is shown. Meanwhile, inFIGS. 5 and 6, a case in which a pair of outermost lines facing eachother in the diagonal direction are connected to each other in the firstlayer in the diagonal direction is shown.

Referring to FIGS. 2B, 3 to 6 in detail, as another example, at leastone sub-outermost line among three winding lines may be connected to thecentral node 1 in the first or second layer in the intersecting section.Here, the sub-outermost line means an inner side directly adjacent tothe outermost line described above. In FIGS. 2B and 3, only a pair ofsub-outermost lines is present in the intersecting section 10, and FIGS.4 to 6, each of two pairs of sub-outermost lines faces each other in theintersecting section 10. In FIG. 2B, a case in which each of the pair ofsub-outermost lines is connected to two points of intermediate nodes 1and 1′ in the first and second layers, and in FIG. 3, a case in whichone of the pair of sub-outermost lines is connected to one point ofintermediate node 1 in the first layer and the other thereof isconnected to one point of intermediate node 1 in the second. In FIGS. 4and 5, a case in which each of two pairs of sub-outermost lines isconnected to two points of intermediate nodes 1 and 1′, and in FIG. 6, acase in which a pair of sub-outermost lines is connected to one point ofintermediate node 1. In FIG. 6, the other node 1′ connects a pair oflines other than the outermost line and the sub-outermost line to eachother.

Further referring to FIGS. 2B, 3, and 5, as an example, the sum of theturn numbers of the primary and secondary side windings is an oddnumber. In this case, at least one pair of outermost lines facing eachother in the diagonal direction in the intersecting section 10 among theodd winding turns may be connected to each other in the first or secondlayer in the diagonal direction. In FIGS. 2B and 3, a pair of outermostlines are connected to each other in the diagonal direction, and in FIG.5, each of two pairs of outermost lines are connected to each other inthe diagonal direction. Further, in the case in which the sum of theturn numbers of the primary and secondary side windings is an oddnumber, the pair of sub-outermost lines facing each other normallydirectly or obliquely in the intersecting section 10 among the oddwinding turns may be connected to each other through the intermediatenode 1 so as not to contact a connection line of the pair of outermostlines in the intersecting section 10. In FIGS. 2B and 3, a pair ofsub-outermost lines faces each other horizontally, and in FIG. 5, eachof two pairs of sub-outermost lines faces each other obliquely and oneof the two pairs of sub-outermost lines are connected to each otherthrough two points of intermediate nodes 1 and 1′. In addition, one ofthe pair of sub-outermost lines may be connected to the intermediatenode 1 in the first layer, and the other thereof may be connected to theintermediate node 1 in the second layer. Here, as an example, in thecase in which the sum of the turn numbers of the primary and secondaryside windings is an odd number, the pair of sub-outermost lines may beconnected to each other at one point of intermediate node 1 or twopoints of intermediate nodes 1 and 1′. Although FIG. 5 shows that thepair of sub-outermost lines are connected to each other at two points ofintermediate nodes 1 and 1′, the pair of sub-outermost lines may also beconnected to each other at one point of intermediate node 1 as shown inFIG. 3.

Further, in the case in which the sum of the turn numbers of the primaryand secondary side windings is an odd number, for example, in the casein which the sum of the turn numbers of the primary and secondary sidewindings is 3, one of the primary and secondary side forms a singleline, and the other thereof forms two lines to have the turn number of2. In the case in which the sum of the turn numbers of the primary andsecondary side windings is 5, one of the primary or secondary side mayform two lines to have the turn number of 2, and the other thereof mayform three lines to have the turn number of 3. In the case in which thesum of the turn numbers of the primary and secondary side windings is 5,any one side having the turn number of 2 may be disposed between lineshaving the turn number of 3. For example, referring to FIG. 5, a signaltransmitted through a line d in any one side of the primary andsecondary sides may be moved through lines b′, b and d′. Alternatively,when signals are input through lines d and d′ in an opposite directionto each other, they are exit from the other terminal or a ground (notshown) through lines b′ and b. Here, remaining lines may form the otherside of the primary and secondary sides, and a transmission signal in aline a may exit while being turned three times through lines c′, c, e′,e, and a′.

Referring to FIG. 5, as another example, the sum of the turn numbers ofthe primary and secondary side windings is an odd number of 5 or more.Here, one of the pair of sub-outermost lines facing each other obliquelyin the intersecting section 10 among the odd winding turns may beconnected to the intermediate node 1 in the first layer, and the otherthereof may be connected to the intermediate node 1 in the second layer.In addition, the remaining lines of the odd winding lines may beobliquely connected to a connection line of the pair of outermost linesin the other layer so as to intersect with the connection line of theoutermost lines on a floor plane in the intersecting section 10. In FIG.5, lines e and a′, which are the outermost lines, are connected to eachother in the first layer, lines d and b′, which are the sub-outermostlines, are obliquely connected to each other through two points ofintermediate nodes 1, and lines a and c′, lines b and d′, and lines cand e′, which are the remaining lines, are connected to each other inthe second layer, which is a layer different from the first layer inwhich the lines e and a′ corresponding to the outermost lines areconnected to each other so as to intersect with a connection line of theline c and e′ on the floor plane.

Further referring to FIGS. 4 and 6, as an example, the sum of the turnnumbers of the primary and secondary side windings is an even number.Here, the intermediate nodes 1 and 1′ may be two points. The two pointsof the intermediate nodes 1 and 1′ may face each other based on thecenter of the intersecting section 10. In addition, at least one pair ofoutermost lines facing each other in the diagonal direction in theintersecting section 10 among the even winding turns may be connected toeach other in the first or second layer in the diagonal direction. InFIG. 4, each of two pairs of outermost lines are connected to each otherin the diagonal direction, and in FIG. 6, only a pair of outermost linesare connected to each other in the diagonal direction.

Further, at least one pair of sub-outermost lines facing each othernormally directly or obliquely in the intersecting section 10 among theeven winding turns may be connected to each other through theintermediate node 1 so as not to contact a connection line of the pairof outermost lines in the intersecting section 10. Here, one of the pairof sub-outermost lines may be connected to the intermediate node 1 inthe first layer, and the other thereof may be connected to theintermediate node 1 in the second layer.

Further referring to FIG. 6, as an example, the sum of the turn numbersof the primary and secondary side windings is an even number of 6 ormore. Here, one of the pair of sub-outermost lines facing each otherobliquely in the intersecting section 10 among the even winding turnsmay be connected to one point of intermediate node 1 in the first layer,and the other thereof may be connected to one point of intermediate node1 in the second layer. In addition, one of another pair of lines (linesd and c′ of FIG. 6) facing each other obliquely in the intersectingsection 10 among the even winding turns may be connected to theintermediate node 1′ in the first layer, and the other thereof may beconnected to the intermediate node 1′ in the second layer. In addition,the remaining lines of the even winding lines may be obliquely connectedto a connection line of the pair of outermost lines in the other layerso as to intersect with the connection line on the floor plane in theintersecting section 10.

Hereinafter, a method of manufacturing a transformer according to asecond exemplary embodiment of the present invention will be described.

In describing the present embodiment, the transformer according to thefirst exemplary embodiment of the present invention described above andFIGS. 1, 2B, and 3 to 6 will be referred. In this case, a descriptionoverlapped with that of the first exemplary embodiment of the presentinvention will be omitted.

Referring to FIGS. 1, 2B, 3 to 6, a method of manufacturing atransformer according to the second exemplary embodiment of the presentinvention, the transformer including a primary side winding having aloop shape and a secondary side winding formed on the same plane as thatof the primary side winding and having the same loop shape as that ofthe primary side winding so as to be electromagnetically coupled to theprimary side winding, the method includes: forming an intersectingsection 10 so that the primary side and secondary side windings havingthe sum of the turn numbers of 3 or more intersect with each other in atwo-layer structure. Here, the secondary side winding is formed on thesame plane as that of the primary side winding in a remaining sectionexcept for at least a section at which it intersects with the primaryside winding.

Referring to FIGS. 2B and 3 to 6, in the present embodiment, theintersecting section 10 includes at least one point of intermediate nodehaving one side connected in a first layer and the other side connectedin a second layer. In the present embodiment, the intersecting section10 includes at least one point of intermediate node 1, such that theintersecting section 10 may have a two-layer structure unlike the caseaccording to the related art even though the primary side and thesecondary side have three or more winding turns. Two points ofintermediate nodes 1 and 1′ are shown in FIGS. 2B and 4 to 6, and onepoint of intermediate node 1 is shown in FIG. 3.

As an example, any one of the primary and secondary side windings may bea balanced signal line and the other thereof may be an unbalanced signalline.

Further referring to FIGS. 2B and 3 to 6, as an example, at least onepair of outermost lines facing each other in a diagonal direction in theintersecting section 10 among three or more winding turns may beconnected to each other in the first or second layer in the diagonaldirection.

In addition, further referring to FIGS. 2B, 3 to 6, as another example,at least one sub-outermost line among three winding lines may beconnected to the central node 1 in the first or second layer in theintersecting section 10.

Referring to FIGS. 2B, 3, and 5 in detail, as an example, the sum of theturn numbers of the primary and secondary side windings is an oddnumber. In this case, at least one pair of outermost lines facing eachother in the diagonal direction in the intersecting section 10 among theodd winding turns may be connected to each other in the first or secondlayer in the diagonal direction. Further, the pair of sub-outermostlines facing each other normally directly or obliquely in theintersecting section 10 among the odd winding turns may be connected toeach other through the intermediate node 1 so as not to contact aconnection line of the pair of outermost lines in the intersectingsection 10. In addition, one of the pair of sub-outermost lines may beconnected to the intermediate node 1 in the first layer, and the otherthereof may be connected to the intermediate node 1 in the second layer.

Further referring to FIGS. 4 and 6, as an example, the sum of the turnnumbers of the primary and secondary side windings is an even number.Here, the intermediate nodes 1 and 1′ may be two points. Here, the twopoints of the intermediate nodes 1 and 1′ may face each other based onthe center of the intersecting section 10. In addition, at least onepair of outermost lines facing each other in the diagonal direction inthe intersecting section 10 among the even winding turns may beconnected to each other in the first or second layer in the diagonaldirection. Further, at least one pair of sub-outermost lines facing eachother normally directly or obliquely in the intersecting section 10among the even winding turns may be connected to each other through theintermediate node 1 so as not to contact a connection line of the pairof outermost lines in the intersecting section 10. In addition, one ofthe pair of sub-outermost lines may be connected to the intermediatenode 1 in the first layer, and the other thereof may be connected to theintermediate node 1 in the second layer.

As set forth above, according to the exemplary embodiments of thepresent invention, the line intersecting structure of the transformerincluding three or more lines of the primary and secondary sides becomesa two-layer structure, making it possible to improve efficiency of thetransformer.

According to the exemplary embodiment of the present invention, atransformer generally connected to an output terminal of a poweramplifier is improved to reduce power loss, thereby making it possibleto improve an output of the power amplifier.

It is obvious that various effects directly stated according to variousexemplary embodiment of the present invention may be derived by thoseskilled in the art from various configurations according to theexemplary embodiments of the present invention.

The accompanying drawings and the above-mentioned exemplary embodimentshave been illustratively provided in order to assist in understanding ofthose skilled in the art to which the present invention pertains ratherthan limiting a scope of the present invention. In addition, exemplaryembodiments according to a combination of the above-mentionedconfigurations may be obviously implemented by those skilled in the art.Therefore, various exemplary embodiments of the present invention may beimplemented in modified forms without departing from an essentialfeature of the present invention. In addition, a scope of the presentinvention should be interpreted according to claims and includes variousmodifications, alterations, and equivalences made by those skilled inthe art.

What is claimed is:
 1. A transformer comprising: a primary side windinghaving a loop shape; a secondary side winding formed on the same planeas that of the primary side winding in a remaining section except for atleast a section at which it intersects with the primary side winding andhaving the same loop shape as that of the primary side winding so as tobe electromagnetically coupled to the primary side winding; and anintersecting section formed so that the primary side and secondary sidewindings having the sum of the turn numbers of 3 or more intersect witheach other in a two-layer structure, wherein the intersecting sectionincludes at least one point of intermediate node having one sideconnected in a first layer and the other side connected in a secondlayer, wherein the secondary side winding intersects with the primaryside winding, wherein the secondary side winding is formed on the sameplane as that of the primary side winding in a remaining section exceptfor at least a section of the intersecting section at which itintersects with the primary side winding.
 2. The transformer accordingto claim 1, wherein at least one pair of outermost lines facing eachother in a diagonal direction in the intersecting section among thethree or more winding turns are connected to each other in the first orsecond layer in the diagonal direction.
 3. The transformer according toclaim 1, wherein at least one sub-outermost line among the three or morewinding turns is connected to the intermediate node in the first orsecond layer in the intersecting section.
 4. The transformer accordingto claim 1, wherein the sum of the turn numbers of the primary andsecondary side windings is an odd number, at least one pair of outermostlines facing each other in a diagonal direction in the intersectingsection among the odd winding turns are connected to each other in thefirst or second layer in the diagonal direction, and a pair ofsub-outermost lines facing each other normally directly or obliquely inthe intersecting section among the odd winding turns are connected toeach other through the intermediate node so as not to contact aconnection line of the pair of outermost lines in the intersectingsection, one of the pair of sub-outermost lines being connected to theintermediate node in the first layer and the other thereof beingconnected to the intermediate node in the second layer.
 5. Thetransformer according to claim 4, wherein the sum of the turn numbers ofthe primary and secondary side windings is an odd number of 5 or more,and one of the pair of sub-outermost lines facing each other obliquelyin the intersecting section among the odd winding turns is connected tothe intermediate node in the first layer and the other thereof isconnected to the intermediate node in the second layer, remaining linesamong the odd winding turns being obliquely connected to each other inthe other layer unlike that of the connection line of the pair ofoutermost lines so as to intersect with the connection line on a floorplane in the intersecting section.
 6. The transformer according to claim1, wherein the sum of the turn numbers of the primary and secondary sidewindings is an even number, the intermediate nodes are two points andface each other based on the center of the intersecting section, atleast one pair of outermost lines facing each other in a diagonaldirection in the intersecting section among the even winding turns areconnected to each other in the first or second layer in the diagonaldirection, and at least one pair of sub-outermost lines facing eachother normally directly or obliquely in the intersecting section amongthe even winding turns are connected to each other through theintermediate node so as not to contact a connection line of the pair ofoutermost lines in the intersecting section, one of the pair ofsub-outermost lines being connected to the intermediate node in thefirst layer and the other thereof being connected to the intermediatenode in the second layer.
 7. The transformer according to claim 6,wherein the sum of the turn numbers of the primary and secondary sidewindings is an even number of 6 or more, one of the pair ofsub-outermost lines facing each other obliquely in the intersectingsection among the even winding turns is connected to one intermediatenode in the first layer and the other thereof is connected to oneintermediate node in the second layer, and one of another pair of linesfacing each other normally directly or obliquely in the intersectingsection among the even winding turns is connected to the otherintermediate node in the first layer and the other thereof is connectedto the other intermediate node in the second layer, remaining linesamong the even winding turns being obliquely connected to each other inthe other layer unlike that of the connection line of the pair ofoutermost lines so as to intersect with the connection line on a floorplane in the intersecting section.
 8. The transformer according to claim1, wherein any one of the primary and secondary side windings is abalanced signal line and the other thereof is an unbalanced signal line.9. The transformer according to claim 2, wherein any one of the primaryand secondary side windings is a balanced signal line and the otherthereof is an unbalanced signal line.
 10. The transformer according toclaim 3, wherein any one of the primary and secondary side windings is abalanced signal line and the other thereof is an unbalanced signal line.11. The transformer according to claim 4, wherein any one of the primaryand secondary side windings is a balanced signal line and the otherthereof is an unbalanced signal line.
 12. The transformer according toclaim 5, wherein any one of the primary and secondary side windings is abalanced signal line and the other thereof is an unbalanced signal line.13. The transformer according to claim 6, wherein any one of the primaryand secondary side windings is a balanced signal line and the otherthereof is an unbalanced signal line.
 14. The transformer according toclaim 7, wherein any one of the primary and secondary side windings is abalanced signal line and the other thereof is an unbalanced signal line.15. A method of manufacturing a transformer including a primary sidewinding having a loop shape and a secondary side winding formed on thesame plane as that of the primary side winding and having the same loopshape as that of the primary side winding so as to beelectromagnetically coupled to the primary side winding, the methodcomprising: forming an intersecting section so that the primary side andsecondary side windings having the sum of the turn numbers of 3 or moreintersect with each other in a two-layer structure, wherein theintersecting section includes at least one point of intermediate nodehaving one side connected in a first layer and the other side connectedin a second layer.
 16. The method according to claim 15, wherein atleast one pair of outermost lines facing each other in a diagonaldirection in the intersecting section among the three or more windingturns are connected to each other in the first or second layer in thediagonal direction.
 17. The method according to claim 15, wherein atleast one sub-outermost line among the three or more winding turns isconnected to the intermediate node in the first or second layer in theintersecting section.
 18. The method according to claim 15, wherein thesum of the turn numbers of the primary and secondary side windings is anodd number, at least one pair of outermost lines facing each other in adiagonal direction in the intersecting section among the odd windingturns are connected to each other in the first or second layer in thediagonal direction, and a pair of sub-outermost lines facing each othernormally directly or obliquely in the intersecting section among the oddwinding turns are connected to each other through the intermediate nodeso as not to contact a connection line of the pair of outermost lines inthe intersecting section, one of the pair of sub-outermost lines beingconnected to the intermediate node in the first layer and the otherthereof being connected to the intermediate node in the second layer.19. The method according to claim 15, wherein the sum of the turnnumbers of the primary and secondary side windings is an even number,the intermediate nodes are two points and face each other based on thecenter of the intersecting section, at least one pair of outermost linesfacing each other in a diagonal direction in the intersecting sectionamong the even winding turns are connected to each other in the first orsecond layer in the diagonal direction, and at least one pair ofsub-outermost lines facing each other normally directly or obliquely inthe intersecting section among the even winding turns are connected toeach other through the intermediate node so as not to contact aconnection line of the pair of outermost lines in the intersectingsection, one of the pair of sub-outermost lines being connected to theintermediate node in the first layer and the other thereof beingconnected to the intermediate node in the second layer.
 20. Thetransformer according to claim 1, wherein the intersecting sectioncomprises a first winding of the primary and secondary side windings onthe first layer of the two-layer structure crossing a second winding ofthe primary and secondary side windings on the second layer of thetwo-layer structure and the one side of the at least one point ofintermediate node connects to a third winding of the primary andsecondary side windings in the first layer crossing the second windingand the other side of the at least one point of intermediate nodeconnects to the third winding in the second layer crossing the firstwinding.
 21. The transformer according to claim 20, wherein the thirdwinding is disposed between the first winding and the second winding onthe same plane in the remaining section.
 22. The transformer accordingto claim 21, wherein the at least one point of intermediate node isdisposed innermost to the first and second windings in the intersectingsection.
 23. The method according to claim 15, wherein the intersectingsection comprises a first winding of the primary and secondary sidewindings on the first layer of the two-layer structure crossing a secondwinding of the primary and secondary side windings on the second layerof the two-layer structure and the one side of the at least one point ofintermediate node connects to a third winding of the primary andsecondary side windings in the first layer to crossing the secondwinding and the other side of the at least one point of intermediatenode connects to the third winding in the second layer to cross thefirst winding.
 24. The method according to claim 23, wherein the thirdwinding is disposed between the first winding and the second winding onthe same plane in the remaining section.
 25. The method according toclaim 24, wherein the at least one point of intermediate node isdisposed innermost to the first and second windings in the intersectingsection.
 26. A transformer comprising: a primary side winding having aloop shape; a secondary side winding having the same loop shape as thatof the primary side winding so that the primary and the secondary sidewindings electromagnetically couple, wherein the secondary side windingintersects with the primary side winding, wherein the secondary sidewinding is formed on the same plane as that of the primary side windingin a remaining section except for at least a section of the intersectingsection at which it intersects with the primary side winding, whereinthe intersecting section includes plural windings, of the primary andsecondary side windings, intersecting each other with respect todifferent layers of a corresponding two-layer structure, wherein theintersecting section includes at least one point of intermediate nodehaving respective sides connected in the different layers, and whereinthe plural windings of the primary and secondary side windings in theintersecting section include a total of 3 or more turns, so as toinclude at least a first, a second, and a third winding.
 27. Thetransformer according to claim 26, wherein the transformer includesplural primary side windings alternatingly formed with plural secondaryside windings except in corresponding intersecting sections.
 28. Thetransformer according to claim 26, wherein respective sides of the atleast one point of intermediate node are connected to the third windingin a first layer to cross the second winding and in the second layer tocross the first winding, and wherein the third winding is disposedbetween the first winding and the second winding on the same plane inthe remaining section.